Alladi Ramakrishnan Hall

A. Gopakumar

TIFR, Mumbai

Blazars are active galactic nuclei with strong jets. Theytend to exhibit dramatic and unpredictable flux variations, namely outbursts.Certain observed outbursts from an exceptional Blazar OJ287can be explained by invoking a massive black hole binaryas its central engine.Detailed General Relativistic modeling allowed us to predict a majoroptical outburst during November 2015. The outburst did occur within the expected time range,peaking on 5/12/2015.A multi-wavelength observational campaign confirmed the occurrence of certain impact flare and the presence of a major thermal component in the flare, as predicted.These observations and subsequent analysis allowed us to establish the presence of a spinning supermassive blackhole binary that spirals in due to the emission of nano-Hertz gravitational wavesin the central engine of OJ287.I will briefly list our on-going efforts that should be interesting to the Event Horizon Telescope consortium and the International Pulsar Timing Array.